The present investigation is based upon the hypothesis that some unidentified environmental factor(s) is etiologically involved with the induction of gastric cancer, and that such agents (chemical, viral, dietary, etc.) are found to a greater extent, or ingested in greater quantities in countries with high gastric cancer mortality. The purpose of this investigation is to epidemiologically characterize the gastric cancer problem in Newfoundland. This will include regional, descriptive and statistical study of this disease throughout this island, which has the highest risk of all Canadian provinces. Further analytical study of environmental factors will be made in this epidemiologically idealized island setting, and will include analysis of trace and major elements in drinking water, dietary factors, occupational risks, etc. In addition, comparative analysis of these factors with other internationally high risk countries will be correlated, including Iceland and Japan.